More than 80% of cancer patients experience pain during the course of their illness or treatment. Despite widespread dissemination and adoption of standard guidelines for cancer pain management, erroneous assessments and subsequent undertreatment and mistreatment of cancer pain are still common occurrences, disproportionately affecting women and ethnic minorities. The purpose of this study is to develop a standardized decision support computer program (DSCP) (an expert system) with self-adaptation capabilities that can be used by nurses as an assessment support tool for dealing effectively with gender and ethnic differences in cancer pain experiences based on cancer patients' own views and experiences. The specific aims are to: a) collect data on cancer pain among four ethnic groups (Hispanic, non-Hispanic Whites, non-Hispanic African-American, and non-Hispanic Asian) in the U.S. and determine gender and ethnic differences in cancer pain experiences; and b) develop a DCSP based on these collected data and feedback from oncology nurses. Using theoretical triangulation, a feminist approach and fuzzy logic will guide the research process. Innovative internet data collection methods will be used including a quantitative Internet survey among 400 cancer patients recruited through general and ethnic-specific Internet Cancer Support Groups, and qualitative online forums of 6-months duration among four ethnically different groups (30 members per group) recruited from among the Internet survey participants. Based on these data, a DSCP will be developed including Knowledge Base Generation, Decision-Making, and Self-Adaptation Modules. Output of this expert system will be classification of patients' pain according to gender and ethnicity with suggested pain management strategies. Online feedback from 30 oncology nurses will be incorporated into the DSCP to increase it acceptability among potential users. Long-term goals are to: a) extend knowledge about gender and ethnic differences in cancer pain experience; b) contribute to recognition of patients' own cancer pain experience so that health care can be planned and provided from patients' own views and perspectives; c) develop a nursing expert system that can effectively guide cancer pain assessment and management in clinical settings; and d) ultimately eliminate gender and ethnic biases and inequity in cancer pain assessment and management.